The sea is turquoise. The sands are white. The beaches are backed by gently swaying palm trees. Welcome to the Florida of Japan, with its marine riches, resort playgrounds and kind climate. Scattered between Taiwan in the south and Japan's larger landmass of Kyushu in the north lie the 360 or so islands of the Okinawa Prefecture. They were once independent domains ruled by castle-dwelling chieftains and dominated by the Ryukyu kingdom, which held sway from the largest of the islands, also called Okinawa.

The sea is turquoise. The sands are white. The beaches are backed by gently swaying palm trees. Welcome to the Florida of Japan, with its marine riches, resort playgrounds and kind climate. Scattered between Taiwan in the south and Japan's larger landmass of Kyushu in the north lie the 360 or so islands of the Okinawa Prefecture. They were once independent domains ruled by castle-dwelling chieftains and dominated by the Ryukyu kingdom, which held sway from the largest of the islands, also called Okinawa.

Although the region officially became part of Japan in 1879, the people here stoically retain their own customs - an idiosyncratic blend of Chinese and Japanese traditions. The southern part of the group, straggling down from Okinawa Island itself, is perhaps the most striking area in terms of both culture and nature, complete with lush vegetation and vibrant coral reefs.

A tropical paradise then? Not entirely. The brutal conflict of 1945 is all that many outsiders know about the islands and, besides, the legacy of the Second World War is still very obvious. But more than that, the charm of the place today hinges largely on the people and their robust recovery after almost total devastation. Okinawa and the more southerly island of Iwo-jima were the only parts of Japan to see ground fighting during the war, and Okinawa was the setting of the largest-scale campaign in the Asia-Pacific region.

During the Battle of Okinawa, a third of the civilian population was killed, trapped in the cross-fire between the invading Americans and the Japanese military. At the large and poignant Memorial Museum on Okinawa Island you learn how whole hillsides were disfigured by relentless American missile attacks; how islanders starved when Japanese troops monopolised foodstores - and forced local people to act as porters; and how many fleeing Okinawans were coerced into committing mass suicide by the retreating soldiers. You also learn how the end of the war did not necessarily terminate the nightmare for the Okinawans, many of whose ancestral lands were subsequently seized by occupying American forces. And, nearly 60 years on, the Americans are still there: drive around Okinawa Island and you can't miss their military bases, housing about 45,000 personnel.

But despite this, the Okinawans living nearby are astonishingly spirited and good humoured. At Ryukyu Mura, near the west coast of Okinawa Island, you chat to cheerful survivors of the war. With drummers and clowns performing a welcoming show, first impressions are that this reconstructed village is simply a theme park. As you wander past the traditional-style wooden houses, elderly people clad in Ryukyu dress call you inside and invite you to watch them dancing and singing. Gradually you realise they have a serious intent of preserving and passing on their culture. Yet genuinely and very chirpily so: some of these 80-year-olds may even demonstrate their well practised techniques for cavorting with sake bottles balanced on their heads.

Over cups of green tea they also talk to you about how, in spite of the destruction, their culture survived the war - and how they have adapted themselves to the subsequent American occupation. Extremely jolly they are, too, delighting in the fact that an entire glassware industry has developed out of recycling pop bottles discarded at the US military bases.

The outlook and energy of these octogenarians is by no means unusual. Okinawans claim to have the longest life-span of all the Japanese (the village of Ogimi in the northern part of Okinawa island has the record for the highest per capita number of residents aged over 100). In a country already notable for longevity it's an impressive record. Locals will proudly tell you it is all down to their diet.

The best way to get an overview of Okinawan cuisine is to inspect the raw ingredients. The food section of the big covered market in the capital, Naha, is a colourful revelation. Among the vivid array here you see vast amounts of pork - trotters, tongue, cheeks, ears and more are avidly consumed; fish of numerous shapes, shades and sizes fresh from the coral reefs; quantities of seaweed - from stringy and crunchy umi budou to a chewy variety known as sea grape or sea caviar; curls of whole, dried habu snake; and tables groaning with fresh noodles. Other shops prominently display tins of spam, the introduction of this processed meat into local dishes being another recent adaptation from the tastes of American residents.

While the Okinawans proudly maintain they have a healthily balanced diet, there's no abstemious pussy-footing here. Beer and awamori, a local high-octane version of sake, is knocked back, and, like elsewhere in Japan, many men smoke like chimneys.

And the Okinawans enjoy a good night out. In Naha, the nightly girl-band gigs at Kaguraza restaurant and bar have become hugely popular. The shows are an engaging mix of youth and tradition, with songs mostly performed to the accompaniment of the sanshin, Okinawa's snakeskin answer to the banjo. Such party spirits may be as likely a cause of longevity as a diet of spam and pigs' ears: despite the horrors of their recent history, the people of islands appear to have found - and retained - an extraordinary gift of happiness.

Rizzan Sea-Park Hotel, Tancha Bay (00 81 98 964 6611; www.rizzan.co.jp). Set beside the sea on the west coast, this enormous resort hotel is almost a village in itself. Doubles from Y9,000 per person (£46).

August Inn, 3-1-10 Kumoji, Naha City (00 81 98 867 8000; www.aug-inn.com). A comfortable town hotel conveniently set in the centre of Naha. Doubles from Y12,500 (£65).

WHAT TO DO

Ryukyu Mura, 1130 Yamada, Onna Village (00 81 98 965 1234; www.ryukyumura.co.jp) Open daily 8.30am-5.30pm, adults Y840 (£4.30). The main point of the village is learn about Ryukyu culture by chatting to the elderly staff: most don't speak English but there are two English-speaking personnel.

Shuri Castle, 1-2 Kinjo-cho, Shuri, near Naha (00 81 98 886 2020; www.shurijo.com) open daily 9am-5.30pm (8.30am-6.30pm in summer), adults Y800 (£4). The original castle of the great Ryukyu kingdom was destroyed in the war, but this reconstruction gives an impression of the size of the place.

WHERE TO EAT

Chi-na Restaurant, 233 Makabe, Itoman-city (00 81 98 997 3207) Itoman in the south of the island was spared serious damage in 1945 and this 1891 house remains more or less as it was built. Five years ago the resident family started serving traditional noodle meals (from 11am-6pm) from around Y600 (£3) per dish.